I have not heard that caffeine was a benzodiazepine receptor antagonist, though it's certainly possible. Double check: doesn't appear to interact directly, but does have somewhat similar properties at least in the long term.
http://molpharm.aspetjournals.org/cgi/content/abstract/33/5/481 Not a viable treatment, I'm afraid. Uncoupling the two should decrease but not eliminate the effects. I'm gonna see about getting the full paper, they should describe any actual decrease in effectiveness. It doesn't make sense to treat benzo withdrawal with a BZD antagonist, though. That'd be like treating morphine withdrawal with naloxone
You say the most hillarious things some times. Seriously, there is no such thing as a benzodiazepine receptor antagonist? The GABA receptor complex is complex, as in not simple at all, but it's such a stupid statement. Do you suppose that BZDs bind to the same site as GABA? They don't.
I'd suggest reading the WIKI entry
here before repeating that.